Siemens last week set out tough new profit targets which look likely to mean more belt-tightening in many of its £2bn UK operations.
British operations generally outperformed their German parent divisions last year. The Germans have been told to improve or be sold off.
Most at risk are transport technology, energy, communications, and semiconductors, all of which have UK manufacturing capacity.
The moves will culminate in a listing for Siemens on the US stock market in the spring of 2001.
Siemens will announce this month how it will dispose of its relay business. It will either be floated off or sold to a trade buyer.